Method of determining position of mark, lithography method, exposure apparatus, and article manufacturing method

ABSTRACT

A method of determining a position of a mark including a first pattern arranged in a first layer of a substrate and a second pattern arranged in a second layer of the substrate, includes determining information concerning the position of the mark as provisional position information based on an image of the mark, acquiring relative position information indicating a relative position between the first pattern and the second pattern, and determining the position of the mark based on the provisional position information and the relative position information.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a method of determining a position of amark, a lithography method, an exposure apparatus, and an articlemanufacturing method.

Description of the Related Art

In recent years, along with high integration and miniaturization of adevice, there is an increasing demand for improvement of overlayaccuracy. An exposure apparatus can execute global alignment ofperforming alignment by measuring, for example, the positions of four toeight alignment marks provided in correspondence with shot regions of asubstrate, and obtaining the first-order component of the array of theshot regions based on the measurement results. There is proposed atechnique in which, in order to implement alignment with high accuracyeven if a distortion (substrate distortion) occurs in an array of shotregions in a device manufacturing process, the positions of a largenumber of alignment marks on the substrate are measured and thesubstrate distortion is corrected with high accuracy (see JapanesePatent No. 6691693). Substrate distortions that can be corrected by theabove-described technique include, in addition the shape of an array ofa plurality of shot regions on a substrate, the shape of each shotregion. For example, in the technique disclosed in Japanese Patent No.6691693, correction of the shape of an array of a plurality of shotregions on a substrate and correction of the shape of each shot regionare performed using information concerning a substrate distortionacquired in advance.

In recent years, to improve the chip yield in a substrate,miniaturization and reduction of the number of alignment marks arrangedon the substrate have been strongly desired. If an overlay inspectionmark formed in a plurality of different layers of a substrate is used asan alignment mark, a pattern region is restricted, as compared with analignment mark in the same occupied region formed in a reference layer,thereby degrading the measurement accuracy and increasing themeasurement time.

SUMMARY OF THE INVENTION

The present invention provides a technique advantageous inminiaturization and reduction of the number of marks arranged on asubstrate.

One aspect of the present invention provides a method of determining aposition of a mark including a first pattern arranged in a first layerof a substrate and a second pattern arranged in a second layer of thesubstrate, comprising: determining information concerning the positionof the mark as provisional position information based on an image of themark; acquiring relative position information indicating a relativeposition between the first pattern and the second pattern; anddetermining the position of the mark based on the provisional positioninformation and the relative position information.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a view showing the arrangement of a measurement apparatusaccording to the first embodiment;

FIG. 1B is a view showing an example of the arrangement of an imagecapturing unit as one of a plurality of components of the measurementapparatus shown in FIG. 1A;

FIGS. 2A and 2B are views each exemplifying an array of a plurality ofshot regions of a substrate;

FIGS. 3A and 3B are views showing an example of the arrangement of anoverlay inspection mark as an alignment mark;

FIG. 4 is a flowchart illustrating measurement processing by themeasurement apparatus according to the first embodiment;

FIGS. 5A to 5C are views for explaining the measurement processing bythe measurement apparatus according to the first embodiment;

FIG. 6 is a flowchart illustrating measurement processing by ameasurement apparatus according to the second embodiment;

FIGS. 7A and 7B are views for explaining the measurement processing bythe measurement apparatus according to the second embodiment;

FIG. 8 is a view showing the arrangement of an exposure apparatusaccording to the third embodiment;

FIG. 9 is a flowchart illustrating exposure processing by the exposureapparatus according to the third embodiment; and

FIG. 10 is a view for explaining a modification of the first embodiment.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference tothe attached drawings. Note, the following embodiments are not intendedto limit the scope of the claimed invention. Multiple features aredescribed in the embodiments, but limitation is not made to an inventionthat requires all such features, and multiple such features may becombined as appropriate. Furthermore, in the attached drawings, the samereference numerals are given to the same or similar configurations, andredundant description thereof is omitted.

First Embodiment

FIG. 1A shows the arrangement of a measurement apparatus 100 accordingto the first embodiment. FIG. 1B shows an example of the arrangement ofan image capturing unit 50 as one of a plurality of components of themeasurement apparatus 100. FIGS. 2A and 2B each show an example of thearrangement of a plurality of shot regions on a substrate 73. FIGS. 3Aand 3B show an example of a mark 72 arranged on the substrate 73. Themeasurement apparatus 100 according to the first embodiment will bedescribed below with reference to these drawings.

The measurement apparatus 100 is a measurement apparatus that measuresthe position of the mark 72 including a first pattern P1 arranged in thefirst layer (target layer) as the reference of the substrate 73 and asecond pattern P2 formed in the second layer different from the firstlayer. As exemplified in FIG. 1A, the measurement apparatus 100 caninclude a substrate stage WS that holds the substrate 73, the imagecapturing unit 50, a controller CU, and an interface UI. The targetlayer is a layer with which an original pattern is to be aligned whentransferring the original pattern to the substrate.

The substrate 73 is a target object for which the shape of the array ofthe plurality of shot regions on the substrate 73 and the shape of eachshot region are measured by the measurement apparatus 100. The substrate73 is, for example, a substrate that is processed to manufacture adevice such as a semiconductor device or a liquid crystal displaydevice. The substrate 73 can be, for example, a wafer or a glasssubstrate.

The substrate stage WS holds the substrate 73 via a substrate chuck (notshown), and is driven by a substrate driving mechanism (not shown). Thesubstrate driving mechanism includes an actuator such as a linear motor,and can drive the substrate 73 held by the substrate stage WS by drivingthe substrate stage WS in the X-axis direction, the Y-axis direction,the Z-axis direction, and the rotation directions around the respectiveaxes. The position of the substrate stage WS can be monitored using, forexample, a 6-axis laser interferometer IF, and controlled by thecontroller CU.

The controller CU can be formed by, for example, a PLD (an abbreviationof Programmable Logic Device) such as an FPGA (an abbreviation of FieldProgrammable Gate Array), an ASIC (an abbreviation of ApplicationSpecific Integrated Circuit), a general-purpose or dedicated computerinstalled with a program, or a combination of all or some of thesecomponents. The controller CU can execute a mark position determinationmethod of determining the position of the mark 72 including the firstpattern P1 arranged in the first layer of the substrate 73 and thesecond pattern P2 arranged in the second layer of the substrate 73. Themark position determination method can include a provisionaldetermination step of determining information concerning the position ofthe substrate 73 as provisional position information based on an imageof the mark 72. The mark position determination method can also includean acquisition step of acquiring relative position informationindicating the relative position between the first pattern P1 and thesecond pattern P2. Furthermore, the mark position determination methodcan include a final determination step of determining the position ofthe mark 72 based on the provisional position information and therelative position information.

The interface UI is a user interface that includes a display device andan input device and is used to transmit information and instructionsfrom the measurement apparatus 100 to the user or from the user to themeasurement apparatus 100. For example, the user can input necessaryinformation to the interface UI via the input device with reference to ascreen provided to the display device. The user can designate, forexample, a shot region where the position of the mark 72 is to bemeasured, among the plurality of shot regions of the substrate 73.

An example of the arrangement of the image capturing unit 50 will bedescribed with reference to FIG. 1B. The image capturing unit 50 caninclude an illumination system that illuminates the substrate 73, animage sensor 75, and an imaging system that images light from the mark72 of the substrate 73 in the image sensor 75. In the example shown inFIG. 1B, the image capturing unit 50 includes a component shared by theillumination system and the imaging system.

The illumination system will be described first. Light from a lightsource 61 is guided to an illumination aperture stop 64 via illuminationoptical systems 62 and 63. The light having passed through theillumination aperture stop 64 is guided to a polarization beam splitter68 via an illumination optical system 65, a mirror 66, and anillumination optical system 67. The polarization beam splitter 68transmits P-polarized light parallel to the X direction and reflectsS-polarized light parallel to the Y direction. The P-polarized lighttransmitted through the polarization beam splitter 68 passes through anaperture stop 69, and is then converted into circularly polarized lightby a λ/4 plate 70, thereby Koehler-illuminates, via an objective opticalsystem 71, the mark 72 formed in the substrate 73.

The illumination system may include a light quantity adjuster (notshown) and/or a wavelength adjuster (not shown). For example, the lightquantity adjuster is configured to arrange, in an optical path from thelight source 61, an ND filter selected from a plurality of ND filtershaving different transmittances, thereby making it possible to adjustthe intensity of light illuminating the substrate 73. The wavelengthadjuster is configured to arrange, in the optical path from the lightsource 61, a plurality of wavelength filters which transmit light beamshaving different wavelength characteristics, thereby making it possibleto adjust the wavelength of light illuminating the substrate 73.

The imaging system will be described below. The light reflected,diffracted, and scattered by the mark 72 on the substrate 73 passesthrough the objective optical system 71 and the λ/4 plate 70 and isguided to the aperture stop 69. The polarization state of the light fromthe mark 72 is circular polarization that is reverse to the circularpolarization of the light illuminating the mark 72. Therefore, if thepolarization state of the light illuminating the mark 72 is clockwisecircular polarization, the polarization state of the light from the mark72 is counterclockwise circular polarization. The light converted fromcircular polarization into S-polarization by the λ/4 plate 70 passesthrough the aperture stop 69, is reflected by the polarization beamsplitter 68, and is guided to the image sensor 75 via an imaging opticalsystem 74.

As described above, in the image capturing unit 50, the polarizationbeam splitter 68 separates the optical path of the light illuminatingthe substrate 73 and the optical path of the light from the substrate73, and an image of the mark 72 on the substrate 73 is formed in theimage sensor 75. Based on a signal waveform obtained by detecting theimage of the mark 72, the controller CU can determine or acquire theposition of the mark 72 in the coordinate system of the image capturingunit 50. The intensity of the signal waveform from the mark 72 can beadjusted by, for example, the light quantity adjuster (ND filter)provided in the illumination system of the image capturing unit 50, theoutput control of the light source 61, and control of the accumulationtime of the image sensor 75. Based on the position of the substratestage WS obtained using the laser interferometer IF and the position ofthe mark 72 in the coordinate system of the image capturing unit 50, thecontroller CU can determine and acquire the position of the mark 72 inthe coordinate system of the substrate stage WS.

In the imaging system of the image capturing unit 50, a detectionaperture stop may be arranged between the polarization beam splitter 68and the image sensor 75. Furthermore, it may be possible to adjust thenumerical aperture of each of the illumination aperture stop 64 and thedetection aperture stop, thereby adjusting a value which is acoefficient representing the ratio of the numerical aperture of theillumination system and the numerical aperture of the imaging system. Anexample of an arrangement for adjusting the numerical aperture is anarrangement in which an aperture stop arbitrarily selected from aplurality of aperture stops can be arranged in the optical path.

The measurement apparatus 100 can be configured to detect, by the imagesensor 75, light (reflected light and scattered light) from the mark 72,or each of the first pattern P1 and the second pattern P2 forming themark 72. As a method of detecting the light from the mark 72, forexample, dark field detection can be adopted in which the aperture stop64 and the detection aperture stop (the numerical apertures of theillumination system and the imaging system) are controlled to block the0-order diffracted light from the mark 72 and detect only thehigher-order diffracted light and scattered light.

The measurement target of the measurement apparatus 100, that is, themark 72 on the substrate 73 will be described below. FIGS. 2A and 2Beach show an example of the array of the plurality of shot regions ofthe substrate 73. In the example shown in FIG. 2A, among the pluralityof shot regions of the substrate 73, shot regions for which measurementprocessing (alignment measurement) is performed are sample shot regions151 to 154. In the peripheral portion of the shot region, a scribe line(not shown) is arranged. If each shot region includes a plurality ofchip regions (regions chipped by dicing), a scribe line (not shown) isarranged between adjacent chip regions. On the scribe line, the mark 72is arranged.

As described above, the mark 72 includes the first pattern P1 arrangedin the first layer (target layer) as the reference of the substrate 73,and the second pattern P2 formed in the second layer different from thefirst layer to be paired with the first pattern P1. That is, the mark 72can be an overlay inspection mark on the substrate 73.

The reason why the mark 72 used to perform alignment with respect to thetarget layer is preferably an overlay inspection mark will now bedescribed. The substrate 73 is a target object for which the shape ofthe array of the plurality of shot regions on the substrate 73 and theshape of each shot region are measured by the measurement apparatus 100.The alignment mark can mainly be provided for measuring the position ofa sample shot region. As for the alignment mark, there are various sizesand designs (measurement is performed individually or simultaneously inthe X direction and the Y direction) corresponding to the processconditions of the substrate, the detection methods of the alignmentoptical system (image capturing unit 50) of the apparatus for processingthe substrate, and the like. However, to improve the chip yield in thesubstrate, the area occupied by the alignment mark needs to bedecreased, thereby imposing a strict restriction on the number ofalignment marks that can be arranged on the scribe line.

On the scribe line between the shot regions, in addition to thealignment mark, an overlay inspection mark for measuring an overlayerror of an evaluation target layer with respect to the target layer isalso arranged. FIGS. 3A and 3B show an example of the overlay inspectionmark for measuring overlay errors in the X direction and the Y directionsimultaneously. The combination of the first pattern P1 provided in thetarget layer and the second pattern P2 in the layer where exposure isnewly performed can form the overlay inspection mark. In overlayinspection, the shape of the sample shot region is an inspection target,and thus a plurality of overlay inspection marks are often provided onthe scribe line. Therefore, by executing alignment using the overlayinspection mark, the shape of each shot region can be measured inaddition to the shape of the array of the plurality of shot regions onthe substrate 73.

In the overlay inspection mark, the first pattern P1 can include aplurality of first partial patterns 301, and the second pattern P2 caninclude a plurality of second partial patterns 302. From one viewpoint,the overlay inspection mark can have a feature that the second patternP2 falls within a rectangular region 300 circumscribing the firstpattern P1. From another viewpoint, the overlay inspection mark can havea feature that at least part of at least one of the plurality of secondpartial patterns 302 is arranged between at least two first partialpatterns 301 among the plurality of first partial patterns 301.

From still another viewpoint, as exemplified in FIGS. 3A and 3B, in theoverlay inspection mark, the first pattern P1 is provided in the targetlayer (first layer) but the second pattern P2 is provided in the layer(second layer) different from the target layer. Thus, if only the firstpattern P1 is used as an alignment mark, the line length in thenon-measurement direction and the number of lines decrease, as comparedwith a case in which an alignment mark in the same occupied region ismeasured, thereby degrading the measurement accuracy. If the number ofalignment marks to be measured and the measurement time are increased,the productivity decreases.

To cope with this, this embodiment provides a measurement method and ameasurement apparatus that can execute measurement at high speed withhigh accuracy even if an overlay inspection mark is used as an alignmentmark. In this embodiment, the mark 72 used as an alignment mark is anoverlay inspection mark including the first pattern P1 arranged in thefirst layer (target layer) as the reference of the substrate 73 and thesecond pattern P2 arranged in the second layer different from the firstlayer.

FIG. 3B schematically shows an example of a section of the substrate 73on which the mark 72 (overlay inspection mark) is formed. In thisexample, the substrate 73 includes three layers of a lowermost layer73B, a first layer 73L as a target layer, and a second layer 73U as alayer positioned by the target layer. A layer which is the target ofalignment when forming a pattern on the substrate is determined inadvance, and is called a target layer. The first pattern P1 of thetarget layer 73L includes, for example, four pattern elements P1 a, P1b, P1 c, and P1 d, and the second pattern of the layer 73U positioned bythe target layer includes, for example, four pattern elements P2 a, P2b, P2 c, and P2 d.

A small positional shift amount (a shift amount from a design value)generated when forming the second pattern may exist between the firstpattern P1 and the second pattern P2. Therefore, it is difficult todirectly use the second pattern P2 as an alignment mark in the targetlayer 73L.

To cope with this, in this embodiment, the controller CU performsconversion processing of converting the position of the second patternP2 into the position of the second pattern P2 in the case in which thesecond pattern P2 is formed without any positional shift from the firstpattern P1. This conversion processing is performed based on therelative position information indicating the positional shift amountbetween the first pattern P1 and the second pattern P2. This makes itpossible to use the second pattern P2 as part of the alignment mark inthe target layer. The relative position information can be acquired byoverlay inspection in the previous step.

The mark position determination method of determining the position ofthe mark 72 and the measurement method of determining the position andshape of the shot region will be described below with reference to FIG.4 . The mark position determination method and the measurement methodare controlled by the controller CU.

In step S201, the substrate 73 is loaded in the measurement apparatus100. In step S202, pre-alignment is executed. More specifically, theposition of a mark for pre-alignment provided on the substrate 73 ismeasured using the image capturing unit 50, and the position of thesubstrate 73 is roughly determined based on the measurement result.Pre-alignment in step S202 can be performed at a low resolution for awide detection range, as compared with capturing of the mark 72 in nextstep S203.

In step S203, the image capturing unit 50 captures the mark 72. Morespecifically, based on the result of the pre-alignment, the substratestage WS is driven to a position at which the image capturing unit 50can capture the selected mark 72 in the selected sample shot region.Then, the image sensor 75 captures an optical image of the selected mark72 in the selected sample shot region on the substrate 73, therebyacquiring a captured image. To capture the mark 72, measurementparameter values such as the wavelength of light illuminating the mark72, a light quantity, the a value, and the focus position (theZ-position of the substrate stage WS) can be adjusted to setting valueswith which the position of the mark 72 can be measured with highaccuracy. The measurement parameter values may be determined in advancebased on the past measurement result of the mark 72 and informationconcerning the structure and the physical characteristic value of thesubstrate 73. A value for controlling the polarization state of lightmay be set as a measurement parameter value. As a practical example, inthe image capturing unit 50 shown in FIG. 1B, a beam splitter can bearranged instead of the polarization beam splitter 68 and a polarizationelement can be formed in the illumination system, thereby switching thepolarization state.

In step S204, based on the image of the mark 72 captured in step S203,information concerning the position of the mark 72 is determined asprovisional position information (that is, the position of the mark 72is provisionally determined) (provisional determination step). In oneexample, the provisional position information can include informationwhich is obtained based on the image of the mark 72 and indicates theposition of the first pattern P1 in the target layer 73L and theposition of the second pattern P2 in the layer 73U positioned by thetarget layer. In this example, in step S204, based on the image of themark 72, the position of the first pattern P1 in the target layer 73Land the position of the second pattern P2 in the layer 73U positioned bythe target layer are measured or determined.

Measurement processing of measuring the position of the first pattern P1and the position of the second pattern P2 in step S204 will now bedescribed with reference to FIGS. 5A to 5C. FIG. 5A exemplifies anoptical image of the mark 72 formed on the image capturing region (imagecapturing surface or detection surface) of the image sensor 75 in theimage capturing unit 50 shown in FIG. 1B. A two-dimensional image sensorincluding the image capturing region formed by a plurality of pixelsarrayed in the X direction and the Y direction can be used as the imagesensor 75. Based on an output (captured image) from the image sensor 75,the controller CU can generate a detection signal including thewaveforms corresponding to the first pattern P1 and the second patternP2.

FIG. 5B exemplifies a detection signal SW1 of the first pattern P1generated when an evaluation region for evaluating the first pattern P1representing the position in the X direction is set with respect to thecaptured image obtained by capturing the mark 72 by the image sensor 75.FIG. 5C exemplifies a detection signal SW2 of the second pattern P2generated when an evaluation region for evaluating the second pattern P2representing the position in the X direction is set with respect to thecaptured image obtained by capturing the mark 72 by the image sensor 75.

Based on the designed position of the mark 72, the controller CU can setevaluation regions W1L and W1R to include first partial patterns P1XLand P1XR forming the first pattern P1, respectively, with respect to theimage capturing region of the image sensor 75. Based on the designedposition of the mark 72, the controller CU can set evaluation regionsW2L and W2R to include first partial patterns P2XL and P2XR forming thesecond pattern, respectively. Each of the detection signals SW1 and SW2can be generated by integrating the signal intensities of the respectivepixels in the set evaluation regions in the Y direction. Note that withrespect to the integration of the signal intensities of the respectivepixels of the image sensor 75, the number of pixels to be integrated ispreferably set based on the dimension information of the mark 72.

As exemplified in FIG. 5B, a waveform S1L included in the detectionsignal SW1 corresponds to the signal intensity of the first partialpattern P1XL of the first pattern P1, and a waveform S1R included in thedetection signal SW1 corresponds to the signal intensity of the firstpartial pattern P1XR of the first pattern P1. The controller CU obtainsa measurement value X1L indicating the central position of the firstpartial pattern P1XL from the waveform S1L, and obtains a measurementvalue X1R indicating the central position of the first partial patternP1XR from the waveform SIR. Based on the measurement values X1L and X1R,the controller CU determines information indicating the position of thefirst pattern P1 in the X direction. FIG. 5C is a view showing thedetection signal SW2 of the second pattern P2. The controller CU candetermine information indicating the position of the second pattern P2in the X direction by the same measurement processing. With respect tothe Y direction as well, the same measurement processing is executed forthe first pattern P1 and the second pattern P2, and the controller CUcan determine information indicating the positions of the first patternP1 and the second pattern P2 in the Y direction.

In step S205, for example, the controller CU acquires relative positioninformation indicating the relative position (positional shift amount)between the first pattern P1 and the second pattern P2 in the sampleshot region measured in advance in overlay shift inspection in theprevious step (acquisition step). The relative position information canbe saved in the memory or storage device of the controller CU. The firstlayer 73L as the target layer includes the plurality of first patternsP1, and the second layer 73U as the layer positioned by the target layerincludes the plurality of second patterns P2. After the first layer 73Land the second layer 73U are formed on the substrate 73, a measurementstep of measuring the relative position can be executed before step S204(provisional determination step). In the measurement step of measuringthe relative position, the relative position between the first patternP1 selected from the plurality of first patterns P1 and the secondpattern P2 corresponding to the selected first pattern P1, among theplurality of second patterns P2, can be measured. The measurement stepis typically part of overlay shift inspection in the previous step butmay be performed after the overlay shift inspection. In step S205, thecontroller CU can acquire the relative position information based on theresult of the measurement step.

In steps S206 and S207, the controller CU determines the position of themark 72 based on the provisional position information determined in stepS204 (provisional determination step) and the relative positioninformation acquired in step S205 (final determination step). In stepS206, the controller CU performs conversion processing of converting theposition of the second pattern P2 as the provisional positioninformation determined in step S204 into the position of the secondpattern P2 in the case in which the second pattern P2 is formed withoutany positional shift from the first pattern P1. For example, theposition of the second pattern P2 determined in step S204 is representedby (Bx, By), and the relative position information (positional shiftamount) acquired in step S205 is represented by (Cx, Cy). In this case,a position (Dx, Dy) of the second pattern P2 in the case in which thesecond pattern P2 is formed without any positional shift from the firstpattern P1 is calculated by:

(Dx,Dy)=(Bx−Cx,By−Cy)

The conversion processing of calculating (Dx, Dy) may be performed basedon an offset value for correcting at least one of:

-   -   a tool induced shift, so-called TIS, which is a measurement        error by the measurement apparatus 100 for measuring the mark        72,    -   a wafer induced shift, so-called WIS, (for example, an error        caused by a difference in the three-dimensional shape of the        surface of the mark 72 for each shot region), which is a        measurement error by a process of processing the substrate 73,        and    -   an error caused by a TIS-WIS interaction between the tool        induced shift (TIS) and the wafer induced shift (WIS).

In step S207, based on the position of the first pattern P1 as theprovisional position information determined in step S204 (provisionaldetermination step) and the position (Dx, Dy) of the second pattern P2having undergone the conversion processing in step S206, the controllerCU determines the position of the mark 72. For example, a position (Ex,Ey) of the mark 72 in the coordinate system of the substrate stage WScan be given by:

(Ex,Ey)=((Ax+Dx)/2+WSx,(Ay+Dy)/2+WSy)

where (Ax, Ay) represents the position of the first pattern P1determined in step S204 (provisional determination step). Furthermore,(WSx, WSy) represents the position of the substrate stage WS at the timeof capturing the mark 72.

For example, a position (ex, ey) of the mark 72 in the coordinate systemof the image capturing unit 50 (the position of the mark 72 in thevisual field of the image capturing unit 50) can be given by:

(ex,ey)=((Ax+Dx)/2,(Ay+Dy)/2)

As described above, as a method of determining the position of the mark72, there is provided a method of using the average value of theposition (Ax, Ay) of the first pattern P1 and the position (Dx, Dy) ofthe second pattern P2 having undergone the conversion processing.Furthermore, as another method, the position of the mark 72 may beobtained by weighting each of the position (Ax, Ay) of the first patternP1 and the position (Dx, Dy) of the second pattern P2 having undergonethe conversion processing. For example, the ratio between the signalintensities or contrasts of the first pattern P1 and the second patternP2, which can be calculated from the detection signal waveforms of thefirst pattern P1 and the second pattern P2 obtained based on thecaptured image of the mark 72, can be used as a weighting evaluationparameter.

In step S208, the controller CU determines whether the positions of allthe marks 72 in all the sample shot regions on the substrate 73 areobtained. Then, if it is not determined that the positions of all themarks 72 in all the sample shot regions on the substrate 73 areobtained, the substrate stage WS is driven to the position for measuringthe position of the next mark 72, and steps S203 to S207 are executedfor the next mark 72. On the other hand, if the positions of all themarks 72 in all the sample shot regions on the substrate 73 areobtained, the process advances to step S209.

In step S209, the controller CU calculates the alignment amount of thesubstrate 73 based on the measured positions of all the marks 72 in allthe sample shot regions. More specifically, based on data of the designcoordinate values and the actual measurement values (differences fromthe design coordinate values) of the marks 72 in the sample shotregions, the alignment amount of the coordinate value of each shotregion can be obtained by a statistic operation such as a least squaremethod. The degree of a model formula used by a least square method isdetermined by the arrangement and number of set sample shot regions. Forexample, if the total number of shot regions on the substrate is 64 andthe number of sample shot regions is 4, as shown in FIG. 2A, the shiftof the substrate and a primary linear component (magnification androtation) are obtained as the alignment amount. If the number of sampleshot regions is set to 16 in the arrangement shown in FIG. 2B, the modelformula representing the alignment amount (dx, dy) of the coordinatevalue of each shot region is given by:

dx=a ₀ +a ₁ ·X+a ₂ ·Y+a ₃ ·X ² +a ₄ ·X·Y+a ₅ ·Y ² +a ₆ ·X ³ +a ₇ ·X ²·Y+a ₈ ·X·Y ² +a ₉ ·Y ³

dy=b ₀ +b ₁ ·X+b ₂ ·Y+b ₃ ·X ² +b ₄ ·X·Y+b ₅ ·Y ² +b ₆ ·X ³ +b ₇ ·X ²·Y+b ₈ ·X·Y ² +b ₉ ·Y ³   (1)

The alignment amount of the coordinate value of each shot region whenall the shot regions on the substrate are set as sample shot regions isobtained by preferably selecting one of the above-described modelformula by a least square method and shift correction for each shotregion.

If the positions of the plurality of marks 72 in the respective sampleshot regions are measured, it is readily understood that correction ofthe shape of each shot region can be executed in addition to theabove-described alignment correction of the coordinate value of eachshot region.

In this embodiment, the controller CU calculates the alignment amount.However, the present invention is not limited to this. For example, thismay be performed by an online host apparatus that also comprehensivelycontrols, via a network, other apparatuses in a factory in which themeasurement apparatus 100 is installed. For example, the calculatedalignment amount is transferred, via the online host, to an exposureapparatus that exposes the substrate 73 in the next step.

In step S210, the substrate 73 is unloaded from the measurementapparatus 100.

As described above, according to this embodiment, even if an overlayinspection mark is used as an alignment mark, measurement can beperformed at high speed with high accuracy.

This embodiment has explained the processing of obtaining a correctionamount for alignment with the target layer in the measurement apparatus100 based on the position of the mark 72 including the first pattern P1and the second pattern P2, but the present invention is not limited tothis.

For example, if the first mark 72 and a second mark 92 simultaneouslyfall within the image capturing region of the image sensor 75 shown inFIG. 10 , the measurement apparatus 100 can determine the position ofeach of the first mark 72 and the second mark 92 based on the abovemethod. In this example, the second mark 92 includes a third pattern P3in the third layer positioned by the target layer, and a first patternP1-3 in the target layer.

More specifically, in step S203, the first mark 72 and the second mark92 in the image capturing region can be captured. Subsequently, in stepS204, based on detection signals generated based on the captured imagesof the marks 72 and 92 in step S203, the positions of a first patternP1-2 and the first pattern P1-3 in the target layer 73L, the secondpattern P2 in the second layer, and the third pattern P3 in the thirdlayer can provisionally be determined.

In step S205, the controller CU acquires, for example, relative positioninformation between the first pattern P1-2 and the second pattern P2 inthe sample shot region measured in advance in overlay shift inspectionin the previous step, and relative position information between thefirst pattern P1-3 and the third pattern P3.

In step S206, the controller CU performs conversion processing of thepositions of the second pattern and the third pattern P3 measured instep S204. The position of the second pattern and the position of thethird pattern after the conversion processing are represented by (Dx,Dy) and (Fx, Fy), respectively.

In step S207, the controller CU determines the position (Gx, Gy) of themark 92 by the same method as that of determining the position (Ex, Ey)of the mark 72. More specifically, for example, the position (Gx, Gy) ofthe mark 92 can by determined by (Gx, Gy)=((Ax+Dx)/2+WSx,(Ay+Dy)/2+WSy).

In step S209, the controller CU can calculate an alignment amount usingboth or the average value of the position (Ex, Ey) of the mark 72 andthe position (Gx, Gy) of the mark 92.

Second Embodiment

The second embodiment will be described below. Matters not mentioned inthe second embodiment can comply with the first embodiment. The secondembodiment will be described with reference to FIG. 6 . The arrangementof a measurement apparatus 100, a substrate 73, and a mark 72 accordingto the second embodiment is the same as in the first embodiment. In thesecond embodiment as well, the position and shape of each shot region ina reference layer (target layer) are measured using the position of themark 72 on the substrate 73, and relative position information between afirst pattern P1 and a second pattern P2 acquired in advance. Steps S301to S303, S305, and S308 to S310 shown in FIG. 6 are the same as stepsS201 to S203, S205, and S208 to S210 described with reference to FIG. 4and a detailed description thereof will be omitted.

In step S304, a controller CU provisionally determines informationconcerning the position of the substrate 73 as provisional positioninformation based on a detection signal generated based on a capturedimage of the mark 72 acquired in step S303 (provisional determinationstep). In the second embodiment, the provisional position information isinformation indicating the position of the mark 72 determined based onboth images of the first pattern P1 and the second pattern P2. In stepS304 (provisional determination step), for example, the provisionalposition information can be determined by processing, by a markdetection module, a mark image formed by both the images of the firstpattern P1 and the second pattern P2. The mark detection module can be amodule that detects the position of a mark based on a provided image.The mark detection module may be a software module or a hardware module.The mark detection module can be configured to detect the position ofthe mark on the assumption that a provided image includes an image ofone mark.

The provisional determination step of determining the informationconcerning the position of the mark 72 as the provisional positioninformation will now be described with reference to FIGS. 7A and 7B.FIG. 7A exemplifies an optical image of the mark 72 formed on the imagecapturing region (image capturing surface or detection surface) of animage sensor 75 shown in FIG. 1B, similar to FIG. 5A. A two-dimensionalimage sensor including the image capturing region formed by a pluralityof pixels arrayed in the X direction and the Y direction can be used asthe image sensor 75. The difference from the first embodiment is thatthe controller CU generates a detection signal for the X direction and adetection signal for the Y direction with respect to the first patternP1 and the second pattern P2 based on an output from the image sensor75.

FIG. 7B shows an example of a detection signal SW3 of the first patternP1 and the second pattern P2 generated when an evaluation region is setat once for a mark representing the position in the X direction withrespect to a captured image obtained by capturing the mark 72 by theimage sensor 75. Based on the designed position of the mark 72, thecontroller CU sets an evaluation region W3L to include a partial patternP1XL of the first pattern P1 and a first partial pattern P2XL of thesecond pattern P2 with respect to the image capturing region of theimage sensor 75. Furthermore, based on the designed position of the mark72, the controller CU sets an evaluation region W3R to include a partialpattern P1XR of the first pattern P1 and a partial pattern P2XR of thesecond pattern P2. The detection signal SW3 is generated by integratingthe signal intensities of the respective pixels in the set evaluationregion in the Y direction. That is, the detection signal is obtainedfrom a composite image of the first pattern P1 and the second patternP2. A positional shift amount generated when forming the pattern existsbetween the partial pattern P1XL of the first pattern P1 and the partialpattern P2XL of the second pattern P2. Therefore, each peak signal ofthe detection signal SW3 includes a positional shift amount between thefirst pattern P1 and the second pattern P2.

In FIG. 7B, a waveform S3L included in the detection signal SW3corresponds to the signal intensity obtained by compositing the partialpattern P1XL of the first pattern P1 and the partial pattern P2XL of thesecond pattern P2. Furthermore, in FIG. 7B, a waveform S3R correspondsto the signal intensity obtained by compositing the partial pattern P1XRof the first pattern P1 and the partial pattern P2XR of the secondpattern P2. The controller CU can obtain a measurement value X3Lrepresenting the central position of a pattern PXL from the waveformS3L, and obtain a measurement value X3R representing the centralposition of a pattern PXR from the waveform S3R. Based on themeasurement values X3L and X3R, the controller CU can determine, asprovisional position information, information concerning the position ofthe mark 72 in the X direction. As for the mark in the Y direction aswell, the controller CU can determine, as provisional positioninformation, information concerning the position of the mark 72 in the Ydirection.

In step S306, the controller CU performs conversion processing ofconverting the position of the mark 72 determined as the provisionalposition information in step S304 into the position of the mark 72 inthe case in which the second pattern P2 is formed without any positionalshift from the first pattern P1. The conversion processing is performedbased on relative position information acquired in step S305. In thesecond embodiment, the conversion processing in step S306 corresponds toa final determination step of determining the position of the mark 72.The position of the mark 72 determined as the provisional positioninformation in step S304 is obtained from a composite detection signalof the first pattern P1 in the target layer (first layer) and the secondpattern P2 positioned with a positional shift from the target layer whenforming the pattern in the second layer. Therefore, the position of themark 72 provisionally determined in step S304 includes an error causedby the positional shift. The conversion processing is processing ofreducing or canceling the error. The position of the mark 72 determinedas the provisional position information in step S304 is represented by(Fx, Fy), and the relative position information (positional shiftamount) acquired in step S305 is represented by (Cx, Cy). In this case,the position (Gx, Gy) of the mark 72 in the case in which the secondpattern P2 is formed without any positional shift from the first patternP1 is calculated by:

(Gx,Gy)=(Fx−Cx/2,Fy−Cy/2)

Note that (Gx, Gy) represents the position of the mark 72 in thecoordinate system of an image capturing unit 50 (the position of themark 72 in the visual field of the image capturing unit 50).

Similar to the first embodiment, the conversion processing ofcalculating (Gx, Gy) may be performed based on an offset value forcorrecting at least one of:

-   -   a tool induced shift, so-called TIS, which is a measurement        error by the measurement apparatus 100 for measuring the mark        72,    -   a wafer induced shift, so-called WIS, (for example, an error        caused by a difference in the three-dimensional shape of the        surface of the mark 72 for each shot region), which is a        measurement error by a process of processing the substrate 73,        and    -   an error caused by a TIS-WIS interaction between the tool        induced shift (TIS) and the wafer induced shift (WIS).

In step S307, based on the position of the mark 72 having undergone theconversion processing in step S306 (the position of the mark 72 in thecoordinate system of the image capturing unit 50), the controller CUperforms conversion into the position of the mark 72 in the coordinatesystem of a substrate stage WS. A position (Hx, Hy) of the mark 72 inthe coordinate system of the substrate stage WS can be given by:

(Hx,Hy)=(Gx+WSx,Gy+WSy)

where (WSx, WSy) represents the position of the substrate stage WS atthe time of capturing the mark 72.

In the second embodiment, the position of the mark is provisionallydetermined based on both the partial pattern of the first pattern andthe partial pattern of the second pattern, and is finally determined bycorrecting the provisionally determined position based on the relativeposition information between the first pattern and the second pattern.

Third Embodiment

As the third embodiment, an exposure apparatus 200 including ameasurement apparatus 100 represented by the first or second embodimentwill be described next. FIG. 8 is a schematic view showing thearrangement of the exposure apparatus 200 according to the thirdembodiment. The exposure apparatus 200 is configured to transfer anoriginal pattern to a substrate including the first layer with the firstpattern and the second layer with the second pattern. The exposureapparatus 200 is an example of a lithography apparatus which is used ina lithography process as a manufacturing process of an article or adevice such as a semiconductor device or a liquid crystal display deviceand forms a pattern on a substrate 83. The exposure apparatus 200exposes a photoresist applied to the substrate 83 via a reticle 31serving as an original, thereby transferring the pattern of the reticle31 to the photoresist. A resist pattern is formed by developing theresist film. A pattern corresponding to the resist pattern can be formedin an underlying layer by etching the underlying layer using the resistpattern.

In this embodiment, the exposure apparatus 200 adopts a step-and-scanmethod, but it can also adopt a step-and-repeat method or other exposuremethods. As shown in FIG. 8 , the exposure apparatus 200 can include anillumination optical system 181, a reticle stage RS that holds thereticle 31, a projection optical system 32, a substrate stage WS thatholds the substrate 83, a position measurement apparatus 120, and acontroller CU.

The illumination optical system 181 is an optical system thatilluminates an illuminated surface using light from a light source unit180. The light source unit 180 includes, for example, a laser. The lasercan be an ArF excimer laser having a wavelength of about 193 nm or a KrFexcimer laser having a wavelength of about 248 nm, but the type of lightsource is not limited to the excimer laser. For example, the lightsource unit 180 may use, as the light source, an F2 laser having awavelength of about 157 nm or extreme ultraviolet (EUV) having awavelength of 20 nm or less.

In this embodiment, the illumination optical system 181 shapes the lightfrom the light source unit 180 into slit light having a predeterminedshape suitable for exposure, and illuminates the reticle 31. Theillumination optical system 181 has a function of uniformly illuminatingthe reticle 31 and a polarizing illumination function. The illuminationoptical system 181 includes, for example, a lens, a mirror, an opticalintegrator, and a stop, and is formed by arranging a condenser lens, afly-eye lens, an aperture stop, a condenser lens, a slit, and an imagingoptical system in this order.

The reticle 31 is made of, for example, quartz. The reticle 31 is formedwith a pattern (circuit pattern) to be transferred to the substrate 83.The reticle stage RS holds the reticle 31 via a reticle chuck (notshown), and is connected to a reticle driving mechanism (not shown). Thereticle driving mechanism includes a linear motor, and can move thereticle 31 held by the reticle stage RS by driving the reticle stage RSin the X-axis direction, the Y-axis direction, the Z-axis direction, andthe rotation directions around the respective axes. Note that theposition of the reticle 31 is measured by a reticle position measurementunit of light oblique-incidence type (not shown), and the reticle 31 isarranged at a predetermined position via the reticle stage RS.

The projection optical system 32 has a function of imaging the lightfrom an object plane in an image plane. In this embodiment, theprojection optical system 32 projects the light (diffracted light)having passed through the pattern of the reticle 31 onto the substrate83, thereby forming the image of the pattern of the reticle 31 on thesubstrate. As the projection optical system 32, an optical system formedfrom a plurality of lens elements, an optical system (catadioptricoptical system) including a plurality of lens elements and at least oneconcave mirror, an optical system including a plurality of lens elementsand at least one diffractive optical element such as kinoform, or thelike is used.

The substrate 83 is a processing target object to which the pattern ofthe reticle 31 is transferred, and can be a wafer, a liquid crystalsubstrate, or another processing target substrate. The substrate stageWS holds the substrate 83 via a substrate chuck (not shown), and isconnected to a substrate driving mechanism (not shown). The substratedriving mechanism includes a linear motor, and can move the substrate 83held by the substrate stage WS by driving the substrate stage WS in theX-axis direction, the Y-axis direction, the Z-axis direction, and therotation directions around the respective axes. Furthermore, a referenceplate 39 is provided on the substrate stage WS.

The position of the reticle stage RS and the position of the substratestage WS are monitored by, for example, a 6-axis laser interferometer IFor the like, and the reticle stage RS and the substrate stage WS aredriven at a constant speed ratio under the control of the controller CU.

The controller CU is formed by a computer (information processingapparatus) including a CPU and a memory and, for example, operates theexposure apparatus 200 by comprehensively controlling the respectiveunits of the exposure apparatus 200 in accordance with a program storedin a storage unit. The controller CU controls exposure processing oftransferring the pattern of the reticle 31 to the substrate 83 byexposing the substrate 83 via the reticle 31. Furthermore, in thisembodiment, the controller CU controls measurement processing in theposition measurement apparatus 120 and correction processing(calculation processing) of a measurement value obtained by the positionmeasurement apparatus 120. In this way, the controller CU also functionsas part of the position measurement apparatus 120.

In the exposure apparatus 200, the light (diffracted light) havingpassed through the reticle 31 is projected onto the substrate 83 via theprojection optical system 32. The reticle 31 and the substrate 83 arearranged in an optically conjugate relationship. The pattern of thereticle 31 is transferred to the substrate 83 by scanning the reticle 31and the substrate 83 at a speed ratio of a reduction ratio of theprojection optical system 32.

The position measurement apparatus 120 is a measurement apparatus formeasuring the position of a target object. In this embodiment, theposition measurement apparatus 120 measures the position of an alignmentmark 82 provided in the substrate 83. The alignment mark 82 is anoverlay inspection mark, similar to the mark 72. The positionmeasurement apparatus 120 can have the same arrangement as that of theabove-described measurement apparatus 100.

The operation of the exposure apparatus 200 when the measurementapparatus 100 of the first embodiment is applied to the positionmeasurement apparatus 120 will be described below with reference to FIG.9 . However, the measurement apparatus 100 of the second embodiment maybe applied to the position measurement apparatus 120. The exposureapparatus 200 performs exposure processing by positioning the pattern ofthe reticle 31 in the layer as the reference of the substrate 83 basedon the position of the alignment mark 82 of the substrate 83. Theexposure processing is performed when the controller CU comprehensivelycontrols the respective units of the exposure apparatus 200. Steps S402to S408 shown in FIG. 9 are the same as steps S202 to S208 describedwith reference to FIG. 4 and a detailed description thereof will beomitted.

In step S401-1, the substrate 83 is loaded in the exposure apparatus200. In step S401-2, calibration is performed. More specifically, basedon the designed coordinate position of the reference mark provided inthe reference plate 39 in the coordinate system of the substrate stageWS, the substrate stage WS is driven so as to position the referencemark on the optical axis of the position measurement apparatus 120.Then, the positional shift of the reference mark with respect to theoptical axis of the position measurement apparatus 120 is measured, andthe coordinate system of the substrate stage WS is reset based on thepositional shift such that the origin of the coordinate system of thesubstrate stage WS coincides with the optical axis of the positionmeasurement apparatus 120. Next, based on the designed positionalrelationship between the optical axis of the position measurementapparatus 120 and the optical axis of the projection optical system 32,the substrate stage WS is driven so as to position the reference mark onthe optical axis of the exposure light. Then, the positional shift ofthe reference mark with respect to the optical axis of the exposurelight is measured via the projection optical system 32 by a Through TheLens (TTL) measurement system. Based on the above result, the baselinebetween the optical axis of the position measurement apparatus 120 andthe optical axis of the projection optical system 32 is determined.

In step S409, the alignment amount of the substrate 83 is calculatedbased on the measured positions of the alignment marks 82 in all thesample shot regions, similar to step S209 shown in FIG. 4 . Steps S403to S409 correspond to an alignment measurement step of determining thepositions of the plurality of shot regions based on the position of themark in each of the plurality of sample shot regions. In step S409,global alignment is performed in which based on data of the designvalues and the actual measurement values (differences from the designcoordinate values) of the alignment marks 82 in the sample shot regions,the shift of the shot region and a primary linear component(magnification and rotation) are obtained. Depending on the number ofmeasurement points of the sample shot regions, the array of the shotregions can be corrected by a multidimensional polynomial like equations(1) in the first embodiment. Furthermore, the alignment amount of thesubstrate can also be obtained by combining the correction value ofglobal alignment by the exposure apparatus and the correction value ofeach shot region or the multidimensional polynomial measured by themeasurement apparatus 100 of the first embodiment.

In step S410, the substrate 83 is exposed while scanning the reticle 31and the substrate 83 in a scanning direction (Y direction) (exposurestep). More specifically, based on the baseline amount in step S401-2and the alignment amount of the substrate in step S409, the substrate 83is aligned with a target position, and the pattern of the reticle 31 istransferred to each shot region of the substrate 83 via the projectionoptical system 32. In step S411, the substrate 83 is unloaded from theexposure apparatus 200.

As described above, according to this embodiment, there can be providedan exposure apparatus capable of performing measurement at high speedwith high accuracy even if an overlay inspection mark is used as analignment mark.

Fourth Embodiment

As the fourth embodiment, an article manufacturing method ofmanufacturing a device (article) using the exposure apparatus accordingto the third embodiment will be described below. The articlemanufacturing method is suitable for, for example, manufacturing anarticle such as a device (a semiconductor device, a magnetic storagemedium, a liquid crystal display device, or the like). The manufacturingmethod includes a step of exposing, by using an exposure apparatus 200,a substrate with a photosensitive agent applied thereon (forming apattern on the substrate), and a step of developing the exposedsubstrate (processing the substrate). In addition, the manufacturingmethod can include other well-known steps (oxidation, film formation,deposition, doping, planarization, etching, resist removal, dicing,bonding, packaging, and the like). The article manufacturing method ofthis embodiment is more advantageous than the conventional methods in atleast one of the performance, quality, productivity, and production costof the article.

Other Embodiments

Embodiment(s) of the present invention can also be realized by acomputer of a system or apparatus that reads out and executes computerexecutable instructions (e.g., one or more programs) recorded on astorage medium (which may also be referred to more fully as a‘non-transitory computer-readable storage medium’) to perform thefunctions of one or more of the above-described embodiment(s) and/orthat includes one or more circuits (e.g., application specificintegrated circuit (ASIC)) for performing the functions of one or moreof the above-described embodiment(s), and by a method performed by thecomputer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s) and/or controlling the one or more circuits to perform thefunctions of one or more of the above-described embodiment(s). Thecomputer may comprise one or more processors (e.g., central processingunit (CPU), micro processing unit (MPU)) and may include a network ofseparate computers or separate processors to read out and execute thecomputer executable instructions. The computer executable instructionsmay be provided to the computer, for example, from a network or thestorage medium. The storage medium may include, for example, one or moreof a hard disk, a random-access memory (RAM), a read only memory (ROM),a storage of distributed computing systems, an optical disk (such as acompact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™),a flash memory device, a memory card, and the like.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2022-010359, filed Jan. 26, 2022, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. A method of determining a position of a markincluding a first pattern arranged in a first layer of a substrate and asecond pattern arranged in a second layer of the substrate, comprising:determining information concerning the position of the mark asprovisional position information based on an image of the mark;acquiring relative position information indicating a relative positionbetween the first pattern and the second pattern; and determining theposition of the mark based on the provisional position information andthe relative position information.
 2. The method according to claim 1,wherein the first layer includes a plurality of first patterns, and thesecond layer includes a plurality of second patterns, the method furthercomprises measuring, after formation of the first layer and the secondlayer on the substrate and before the determining the information, arelative position between a first pattern selected from the plurality offirst patterns and a second pattern corresponding to the selected firstpattern among the plurality of second patterns, and in the acquiring,the relative position information is acquired based on a result of themeasuring.
 3. The method according to claim 1, wherein the provisionalposition information provisionally determined in the determining theinformation includes information concerning a position of the firstpattern and a position of the second pattern, which is obtained based onthe image of the mark.
 4. The method according to claim 3, wherein inthe determining the position of the mark, based on the relative positioninformation, conversion processing of converting the position of thesecond pattern determined in the determining the information into theposition of the second pattern in a case in which the second pattern isformed without any positional shift from the first pattern is performed,and the position of the mark is determined based on the position of thefirst pattern determined in the determining the information and theposition of the second pattern having undergone the conversionprocessing.
 5. The method according to claim 4, wherein the conversionprocessing is performed based on an offset value for correcting at leastone of a tool induced shift which is a measurement error by ameasurement apparatus for measuring the mark, a wafer induced shiftwhich is a measurement error by a process of processing the substrate,and an error caused by an interaction between the tool induced shift andthe wafer induced shift.
 6. The method according to claim 4, whereinwhen the position of the mark is determined based on the position of thefirst pattern determined in the determining the information and theposition of the second pattern having undergone the conversionprocessing, the position of the first pattern determined in thedetermining the information and the position of the second patternhaving undergone the conversion processing are weighted.
 7. The methodaccording to claim 1, wherein the provisional position informationprovisionally determined in the determining the information isinformation indicating the position of the mark determined based on bothimages of the first pattern and the second pattern.
 8. The methodaccording to claim 1, wherein in the determining the information, theprovisional position information is determined by processing, by a markdetection module, a mark image formed by both images of the firstpattern and the second pattern, and the mark detection module is amodule configured to detect a position of a mark based on a providedimage.
 9. The method according to claim 7, wherein in the determiningthe position of the mark, the position of the mark is finally determinedbased on an offset value for correcting at least one of a tool inducedshift which is a measurement error by a measurement apparatus formeasuring the mark, a wafer induced shift which is a measurement errorby a process of processing the substrate, and an error caused by aninteraction between the tool induced shift and the wafer induced shift.10. The method according to claim 1, wherein the first pattern and thesecond pattern correspond to a mark for measuring an overlay errorbetween the first layer and the second layer.
 11. The method accordingto claim 10, wherein in the mark, the second pattern falls within arectangular region circumscribing the first pattern.
 12. The methodaccording to claim 10, wherein the first pattern includes a plurality offirst partial patterns, and the second pattern includes a plurality ofsecond partial patterns, and in the mark, at least part of at least oneof the plurality of second partial patterns is arranged between at leasttwo first partial patterns among the plurality of first partialpatterns.
 13. A lithography method of transferring an original patternto a substrate including a first layer with a first pattern and a secondlayer with a second pattern, comprising: determining a position of amark including the first pattern and the second pattern in accordancewith the method of determining the position of the mark defined in claim1; and transferring the original pattern to the substrate by aligningthe original pattern with the first layer based on the position of themark determined in the determining.
 14. The method according to claim13, wherein the substrate includes a plurality of shot regions, and inthe determining the position of the mark, relative position informationis acquired by measuring a relative position between the first patternand the second pattern in a plurality of sample shot regions among theplurality of shot regions.
 15. The method according to claim 14, furthercomprising determining positions of the plurality of shot regions basedon the position of the mark in each of the plurality of sample shotregions, wherein the transferring includes exposing the plurality ofshot regions based on a result of the determining the positions of theplurality of shot regions.
 16. The method according to claim 13, whereinthe determining the position of the mark includes acquiring an image ofthe mark by capturing the mark on the substrate held by a substratestage, and in the determining the position of the mark, the position ofthe mark in a coordinate system of the substrate stage is determinedbased on the position of the mark and a position of the substrate stageat the time of performing the acquiring.
 17. An exposure apparatus fortransferring an original pattern to a substrate including a first layerwith a first pattern and a second layer with a second pattern,comprising: an image capturing unit configured to capture a markincluding the first pattern and the second pattern; and a controllerconfigured to determine, as provisional position information,information concerning a position of the mark based on an image of themark captured by the image capturing unit, determine the position of themark based on the provisional position information and relative positioninformation indicating a relative position between the first pattern andthe second pattern, and control exposure processing for a shot region ofthe substrate based on the position of the mark.
 18. An articlemanufacturing method comprising: forming a resist pattern on a substratein accordance with a lithography method defined in claim 13; andobtaining an article by processing the substrate on which the patternhas been formed.